JPH0127102B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Polyethylene terephthalate (PET) has become an important raw material for the production of molded articles, films and fibers. For the synthesis of PET, see, inter alia, U.S. Pat. No. 2,465,319 to Whinfield et al. and U.S. Pat. Encyclopedia of Chemical Technology
Chemical Technology), 2nd edition, Volume 16, No.
It is described from page 159 onwards (1968). These are cited and referred to in the present invention. Many applications for injection and extrusion parts require heat resistance;
PET can exhibit certain undesirable properties. Unreinforced PET has shown limited interest in manufacturing such parts due to its low HDT (heat deflection temperature) - about 75°C at 264 psi. HDT is a measure of an important thermal property of a thermoplastic material that allows a bar of that material to be tested under a constant load (usually
When held in bending (at 264 psi or 66 psi) and there is a specified amount of deformation, the temperature at which this specified deformation occurs is the HDT - Billmeyer
See John Wiley and Sons, Inc., 1962, Textbook of Polymer Science, page 112. The present invention provides a thermoplastic molding composition comprising an intimate mixture of (a) polyethylene terephthalate and (b) a copolymer of a vinyl aromatic compound and an imide derivative of an ethylenically unsaturated dicarboxylic acid. The mixed composition of the present invention is prepared according to ASTM operating method D648-72.
It has a heat deflection temperature of at least about 80°C, preferably greater than about 90°C, at 264 psi, as measured by . In yet another preferred embodiment, the copolymer is a copolymer of styrene, preferably a copolymer of styrene and maleimide. Yet another aspect of the invention is when the copolymer is a rubber modified copolymer. The polyethylene terephthalate used in the present invention is preferably a PET homopolymer.
Halogenated PET can also be used, typically halogenated, preferably brominated terephthalic acids (e.g. 2,5-dibromoterephthalic acid and 2,3,5,6-tetrabromoterephthalic acid). and by condensation of a mixture of terephthalic acid and ethylene glycol. Furthermore, the polyethylene terephthalate used in the present invention contains up to 10 mol% of the acid component, such as phthalic acid, isophthalic acid, naphthalene-2,6
-dicarboxylic acids, diphenyl-4,4'-dicarboxylic acids and similar acids, as well as their halogenated counterparts. This copolymer still contains up to 10 mol% of the glycol component, e.g. bis(2-hydroxyethyl) of propylene glycol, butylene glycol, dibromoneopentyl glycol, tetrabromobisphenol A.
It may also contain other glycol groups such as ether and tetrabromo-p-xylene glycol. Kirkootmar's Encyclopedia of Chemical Technology, Vol.
16, pp. 161-173 (1968). The polyethylene terephthalate used in this invention must be moldable. In a preferred embodiment, these polyesters are 60
Approximately 0.25 when measured at 25°C using 0.25 g of polyester per 100 ml of a solvent consisting of % by weight phenol and 40% by weight tetrachloroethane.
It has an intrinsic viscosity (IV) of between 1.5 and most preferably between about 0.5 and 1.2. The amount of polyethylene terephthalate resin used in the blended compositions of the present invention ranges from about 10 to about 90% by weight, based on the total weight of resin in the blend, and the amount of unsaturated cyclic imide copolymer ranges from about 10 to about 90% by weight, based on the total weight of resin in the blend. about 90 to about 10% by weight based on the total weight of resin in the mixture
It is preferable that it is in the range of . In particularly preferred embodiments, the relative amounts of PET and copolymer range from about 20 to about 80% by weight and from about 80 to about 20% by weight, respectively. However, their sum is equal to 100. The most preferred relative amounts used are 30 each
~70% by weight and in the range of about 70-30% by weight. The vinyl aromatic compound of component (b) has the formula (wherein R ¹ and R ² are selected from the group consisting of (lower) alkyl groups having 1 to 6 carbon atoms and hydrogen; R ³ and R ⁴ are chlorine, bromine, hydrogen and 1 to 6 carbon atoms. R ⁵ and R ⁶ are selected from the group consisting of hydrogen and (lower) alkyl groups of 1 to 6 carbon atoms, or R ⁵ and R ⁶ are selected from the group consisting of hydrocarbyl groups; which can be linked together to form a naphthyl group). These compounds do not contain substituents with tertiary carbon atoms. Styrene is the preferred vinyl aromatic compound. The α,β-unsaturated cyclic imide of component (b) is preferably an amine nitrogen derivative of an ethylenically unsaturated dicarboxylic acid. For example, the term cyclic imide has the formula (wherein the dotted line represents a carbon-to-carbon single or double bond; R ⁷ is selected from the group consisting of hydrogen, alkyl or aryl groups containing up to 8 carbon atoms; R ⁸ is hydrogen, vinyl, selected from the group consisting of alkyl, alkenyl, alkylcarboxyl or alkenylcarboxyl having 1 to 12 carbon atoms; R ⁹ is selected from the group consisting of hydrogen, lower alkyl, cycloalkyl or aryl; and n is 0 to about 10 is an integer of ). Examples of this are maleimide, methylmaleimide, dimethylmaleimide, N-methylmaleimide, phenylmaleimide and mixtures thereof. Maleimide is the preferred cyclic imide for component (b). Regarding this, the US patent number
Reference is made to specification No. 3840499. Copolymers comprising component (b) include rubber-modified copolymers. In the production of these rubber-modified copolymers, polybutadiene, isobutylene-isoprene copolymers, styrene-butadiene copolymers, butadiene copolymers, butadiene-acrylonitrile copolymers, ethylene-propylene copolymers, polyisoprene Rubbers such as ethylene-propylene-diene monomer terpolymers (EPDM) and similar copolymers can be used. See US Pat. No. 3,998,907 in this regard. The copolymer of component (b) contains about 40 to 5 parts by weight of α, β-
It can consist of an unsaturated cyclic imide, 60-95 parts by weight vinyl aromatic compound and 0-50 parts by weight rubber. Preferred polymers have a relative proportion of vinyl aromatic compound and imide of about 90 to about 90, respectively.
70% by weight and in the range of about 10 to about 30 parts by weight. The rubber-modifying polymer used in the present invention includes about 5 to 25 parts by weight of an α,β-unsaturated cyclic imide, 40 to 85 parts by weight of a vinyl aromatic compound, and about 5 to 25 parts by weight of an α,β-unsaturated cyclic imide;
Preferably, it contains up to about 30 parts by weight of rubber. Preferred unmodified vinyl aromatic compound-α,β-unsaturated cyclic imide copolymers used in the compositions of the present invention are manufactured by Arco Polymers.
Dylark DKB176 supplied by
It is. Dylarc DKB176 is a styrene compound that contains approximately 17% maleimide and the remainder is styrene.
It is said to be a maleimide copolymer. A preferred rubber modified vinyl aromatic compound-α,β-unsaturated cyclic imide copolymer is Dilarc DKB162, supplied by Alco Polymers. This is about 15
It is said to be a styrene-malemid copolymer, containing 11% rubber and 11% maleimide, with the remainder being styrene. The compositions of the invention may also contain other ingredients for their common use, such as flame retardants, fillers, processing aids, pigments, stabilizers and similar additives. Carbon filaments, silicates such as acicular calcium silicate, asbestos, titanium dioxide, potassium titanate and reinforcing fillers such as titanate whiskers, glass flakes and fibers may also be used in amounts sufficient to impart reinforcing properties. can be used. Particularly preferred compositions of the present invention include impact modifiers. Examples of impact modifiers include ethylene/vinyl acetate copolymers, ethylene/acrylic acid copolymers (with some neutralized acid functionality), ethylene/methacrylic acid copolymers (with some neutralized acid functionality), and ethylene/methacrylic acid copolymers (with some neutralized acid functionality). with a methacrylic acid functional group),
Ethylene/alkyl acrylate/methacrylic acid terpolymers (also with some neutralized methacrylic acid functionality), ABS, polyethylene oxide, styrene-butadiene-styrene (S-B
-S) Block copolymer, styrene/butadiene multi-block copolymer, styrene/butadiene radical block copolymer, halogenated S-B-
S block copolymer, styrene/butadiene rubber, acrylic rubber, EPDM, ethylene/acrylic acid copolymer, ethylene/methyl acrylate copolymer, ethylene/ethyl acrylate copolymer, polyester-ether multi-block copolymer and similar polymers. Although these materials are available in a wide range of molecular weights, it is generally desirable for the impact modifier to have a melt viscosity close to that of the base material when used. The amount of impact modifier generally ranges from about 5 to about 40% by weight. For protection against thermal-oxidative deterioration, the compositions of the present invention contain conventional amounts of stabilizers, preferably from 0.001 to 0.5 for the unfilled and unreinforced compositions of the present invention.
% by weight of stabilizers can be added. Examples of suitable stabilizers are phenols and phenolic derivatives, preferably sterically hindered phenols containing alkyl substituents with 1 to 6 carbon atoms in two positions ortho to the phenolic hydroxyl group;
Amines, preferably secondary arylamines and their derivatives, phosphates and phosphites, preferably their aryl derivatives, and quinones. A non-limiting example is 4,4′-bis(2,6
-di-tert-butylphenol), 1,3,5-
Trimethyl-2,4,6-tris (3,5-di-
tert-butyl-4-hydroxybenzyl)benzene, 4,4'-butylidene-bis-(6-tert-butyl-m-cresol), 3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid diethyl ester , N,N′-bis-(β-naphthyl)
-p-phenylenediamine, N,N'-bis-
(1-methyl-heptyl)-p-phenylenediamine, phenyl-β-naphthylamine, 4,4'-
Bis-(α,α-dimethylbenzyl)-diphenylamine, hydroquinone, p-benzoquinone,
These include toluhydroquinone, p-tert-butylpyrocatechol, chloranil and naphthoquinone. Flame retardants that can be used in the compositions according to the invention consist of a large number of compounds familiar to those skilled in the art. Generally, these flame retardants contain chemical elements such as bromine, chlorine, antimony, phosphorus and nitrogen, which are used for their flame retardant abilities. These flame retardants are optionally used together with auxiliary compounds, sometimes referred to as synergists, such as bromine- and/or chlorine-containing organic compounds (antimony trioxide, zinc borate, etc.). or elemental phosphorus or ammonium polyphosphates, various bromine- and/or chlorine-containing organic phosphate esters, phosphorus compounds such as hexaphenoxyphosphazene, and similar materials. Preferred reinforcing fillers are glass fibers, mineral fillers, finely divided fillers such as mica, and similar fillers. Generally speaking, the glass filament is approximately 50% based on the total amount of glass and resin.
Optimal physical properties can be obtained when used in amounts of ~40% by weight. However, it is also possible to use larger amounts. The compositions of the invention are prepared by mixing the components in a mixer (e.g. a Henschel mixer) and extruding the mixture in an extruder (e.g. a 28 mm Werner Pfleiderer extruder with twin screws). ) can be prepared by blending. The extrudate is then cut into pellets and molded in an injection molding machine. The invention is further illustrated in the following examples.
However, these examples should not be construed as limiting the invention. In the examples, all parts are by weight. Examples 1-3 The compositions of the following examples were prepared by mixing the components to form a premix, compounding the premix in a screw extruder at a temperature of about 525° to 550° (274° to 288°C), and The pellets are then processed into a New Britain injection molding machine.
The samples were prepared by molding them into test bars using a molding machine. The individual materials used in these compositions were as follows. a Polyethylene terephthalate; Goodyear Tire and Rubber Co., Ltd.
Tire and Rubber Company); VFR2977A - Solvent 100 consisting of 60% phenol and 40% tetrachloroethane by weight
Crystalline PET with an intrinsic viscosity of 0.68±0.025 when measured at 25°C using 0.25g polyester per ml. b Rubber modified styrene/maleimide copolymer; Manufactured by Alco Polymers; Dilarc DKB162-
A rubber-modified styrene/maleimide copolymer containing 11% maleimide, 15% rubber, and the remainder styrene. c Styrene/maleimide copolymer; manufactured by Alco Polymers; Dilarc DKB176 contains 17% maleimide and the remainder is styrene. The following table shows the composition (parts or weight %) of the formulations. [Table] Imide
c. Styrene/maleimide None 30 40
Test bars of the above compositions were tested according to ASTM procedures to evaluate physical properties. The ASTM designation numbers for the properties measured were as follows. Specific gravity…D792-66 (1975); Tensile-yield, elongation and tensile modulus…D638-77a; Bending strength and bending modulus…D790-71 (1978); 1/4″ bar and 40°C
Izot impact of 1/8″ bar in…D256―
78; Heat deflection temperature...D648-72 (1978); Vicat softening point...D1525-76; and Rockwell hardness...
D785-65 (1976). The results are shown in Table 1. [Table] Comparative example: When measured at 25°C using 0.25g of polyester per 100ml of a solvent consisting of 60% by weight of phenol and 40% by weight of tetrachloroethane.
PET having an intrinsic viscosity of 0.59 was molded in the manner outlined in Examples 1-3. ASTM for Examples 1-3
This pure PET is tested for physical properties by operation method.
HDT at 264psi - HDT at 66psi at 76℃
- 104°C, 1/8" bar notched isot impact - 0.6 ft - 1 b/in, bending strength - 15,200 psi and bending modulus - 400,000 psi. Example 4 PET and rubber modification of Example 1 Test bars were prepared from a blend of 30 parts maleimide copolymer and 70 parts PET using a maleimide copolymer and compounding and molding operations. Typical properties of these specimens are shown in Table 1. Table Bending Strength, psi 2.000 Flexural Modulus, 10 ³ psi 419 Izot Impact, 1/8" Bar, ft-1b/in 0.5 Heat Deflection Temperature at 264 psi, °C 86 Heat Deflection Temperature at 66 psi, °C 124 Example 5 -8 Four formulations of the present invention were prepared by extrusion compounding using an NRM extruder equipped with multiple screen packs. Two of these formulations were made by compounding the PET and maleimide copolymers in one pass through an extruder. The other two formulations were passed through the extruder twice. The PET used in these formulations was manufactured by American Hoechst.
It had an average intrinsic viscosity of about 0.6, a TiO ₂ content of about 0.3% by weight, and a Gardner yellowness index of 12. This was a regular textile product. The Reimide copolymer used was Example 1.
It was the same rubber-modified product as that used in . The table below is an identification of these formulations and the table shows illustrative properties of test specimens molded from these formulations. [Table] [Table] Deflection temperature, °C
Various modifications can be made to the present invention without departing from the scope of the invention as set forth in the claims.

Claims (1)

[Scope of Claims] 1. The following components (a) polyethylene terephthalate, and (b) (i) 60 to 95 parts by weight of a vinyl aromatic compound, α,
(ii) an intimate mixture of a rubber-modified copolymer in which said copolymer is modified with up to 50% by weight of a rubber component; , the relative proportions of (a) and (b) are in the range of 55-70% by weight for (a) and 45-30% by weight for (b), and (a)
A thermoplastic molding composition characterized in that the sum of and (b) is equal to 100. 2 When measuring using ASTM procedure D648-72
The composition of claim 1 having a heat deflection temperature of at least about 90° C. at 264 psi. 3. A composition according to claim 1, wherein (b) is a copolymer of styrene and maleimide or a rubber-modified copolymer. 4. Polyethylene terephthalate has an intrinsic viscosity of about 0.5 to 1.2 when measured at 25°C using 0.25 g of polyester per 100 ml of a solvent consisting of 60% by weight phenol and 40% by weight tetrachloroethane, and (b) a copolymer, and the relative proportions of vinyl aromatic compound and imide in the copolymer are in the range of about 90 to about 70% and about 10 to about 30% by weight, respectively, and the composition The composition of claim 1, wherein the composition has a heat deflection temperature of at least about 90° C. at 264 psi as measured by ASTM operating method D648-72. 5. the polyethylene terephthalate has an intrinsic viscosity of about 0.5 to 1.2 when measured at 25°C using 0.25 g of polyester per 100 ml of a solvent consisting of 60% by weight phenol and 40% by weight tetrachloroethane, and (b) The composition of claim 1, wherein the composition consists essentially of a copolymer of styrene and maleimide having a proportion by weight of styrene of about 90% to about 70% and maleimide of about 10% to about 30% by weight. thing. 6 (b) is a rubber-modified copolymer, and about 5 to
A composition according to claim 1 containing 25 parts by weight of cyclic imide, 40 to 85 parts by weight of vinyl aromatic compound and 5 to 30 parts by weight of rubber. 7. Polyethylene terephthalate has an intrinsic viscosity of about 0.5 to 1.2 when measured at 25°C using 0.25 g of polyester per 100 ml of a solvent consisting of 60% by weight phenol and 40% by weight tetrachloroethane, (b) is about 5 to 25 for rubber-modified copolymers.
parts by weight of a cyclic imide, 40 to 85 parts by weight of a vinyl aromatic compound, and 5 to 30 parts by weight of rubber, and the composition is heated to at least about 90°C at 264 psi as measured by ASTM Procedure D648-72. A composition according to claim 1 having a deflection temperature. (b 2. The composition of claim 1, wherein ) consists essentially of a rubber-modified copolymer of styrene and maleimide.